Intravenous infusion therapy is prescribed where it is desirable to administer medications and other fluids directly into the circulatory system of a patient. It is estimated that approximately forty percent of U.S. hospital patients presently receive some form of infusion therapy and it is expected that the proportion will grow in the future due to the improved health care that results from such therapy.
For many clinical procedures, it is desirable to intravenously administer several fluids to a patient. Plural independent gravity flow controllers and plural independent electronic pumps have heretofore been employed for this purpose. The plural gravity flow controllers, however, are disadvantageous, among other things, due to the increased possibility of infection occasioned by multiple IV venipuncture; due to the flow inaccuracies occasioned, among other things, by patient movement induced tube occlusion or tubing shape changes; due to the considerable labor and time required from a nurse or other health practioner to manually control the plural gravity flow controllers in accordance with a prescribed course of therapy; due to clutter around the patient; and due to the possibility of out-of-control infusion occasioned by a failure of one or more of the gravity flow controllers. The plural independent pumps are disadvantageous, among other things, due to the clutter around the patient occasioned by the use of plural pumps; due to the increased possibility of infection occasioned by multiple IV venipuncture; due to the comparatively high cost of procuring and maintaining several pumps for each such patient; due to the incapability of the heretofore known pumps to administer more than two infusates in time sequence without additional pumps; due to the incapability of the heretofore known pumps to administer dilutions; due to the considerable time and labor required by the health practioner to program and to supervise the plural independent pumps; and due to the comparatively high cost incurred in maintaining an inventory of tubes and administration sets that must be replaced periodically to avoid infection for each pump, fluid, and patient, often amounting on an annual basis to about one half the cost of the pumps themselves.